Maternal emotional availability at bedtime and infant cortisol at 1 and 3 months

Previous work has shown that early experience influences infant cortisol secretion. Few studies, however, have examined associations between parenting quality and cortisol levels and patterning in very young infants.

Aims

This study examined linkages between maternal emotional availability (EA) during a routine caregiving task, bedtime, and infant cortisol in the first 3 months of life. Concurrent and longitudinal associations between maternal EA and infant cortisol were examined.

Study design

Families were visited when their infants were 1 and 3 months old. Video equipment was set up in order to record the infant's bedtime routine. Parents were provided with materials with which to take saliva samples from their infants at late afternoon, bedtime, and the following morning.

Subjects

At 1 month, participants were 96 mothers and infants living in a rural U.S. state. Data were available for 88 mothers and infants at 3 months.

Outcome measures

Maternal EA was scored from videotapes of bedtime at each age point. Infant cortisol was assessed from the saliva samples taken by parents.

Results

Regression analyses indicated that at 1 and 3 months of age, infants of more emotionally available mothers showed lower levels of cortisol secretion across the night than infants of less emotionally available mothers. Additionally, multilevel model analyses indicated that infants of more emotionally available mothers showed greater evidence of a decline in their cortisol levels across the evening, followed by an increase across the nighttime into the morning in their cortisol at 3 months.

Conclusions

Findings suggest that maternal care in the context of a routine caregiving task is associated with lower stress reactivity and with earlier circadian patterning in very young infants.